1. Field of Invention
The present invention relates to an electronic keyboard for a typewriter, a calculating machine, accounting machine or similar office machines, including a plurality of keys, a plurality of actuators connected by means of spring to the said keys, retaining means which hold the said actuators in the rest position and a plurality of circuit elements activated by the said actuators to generate the corresponding electrical signals, and in which each keys, during its depression, loads the spring of the corresponding actuator for the activation of the actuator itself.
2. Description of the Prior Art
A keyboard of the above type is already known in which each actuator has fised to it a permanent magnet which, acting in unison with the metallic structural of the keyboard itself, holds the actuator in the rest position. In this keyboard, at the depression of a key the spring which connects the key itself to the actuator, is loaded, until the force applied by the spring to the actuator is such to overcome the attraction of the permanent magnet. In this manner the actuator is moved by the spring itself through the dynamic energy which it had stored up.
In a keyboard of this type, the releasing action depends exclusively on the force applied by the loaded spring. Therefore the stroke distance of the various keys may differ. This means that if the same stroke distance is required for all the key, all the springs and magnets must be precision set, thus inevitably causing the production of the keyboard to become expensive.